1. Field of the Invention
The present invention relates to devices for operating touch screens. More specifically, the present invention relates to a device for modifying a writing instrument so as to be useable as a device for operating controls on a screen of an automated data device.
2. Background Art
Personal data devices for storing and handling information have come into widespread use in recent years. Some devices have been developed that are intended to assist individuals as automated secretaries (also known as "personal digital assistants" or PDAs). An example is a device known as an electronic notebook. An electronic notebook is a data processing device that has a microprocessor and a display screen, and is adapted to store information and to categorize or otherwise handle the information. Personal data devices may be programmed to enable a user to enter data and control commands that determine how the data is entered, stored, and manipulated. Examples of personal data devices include the Palm series, marketed by 3Com Corp. of Santa Clara, Calif. Apple Computers additionally markets the Newton MessagePad. Other similar products are available on the market. Applications for these devices are growing on a daily basis.
Typically, such devices receive control commands via very small electrical switches, called microswitches, which are integrated into the display screen. A user inputs commands and information into the device by touching a portion of the display screen where a microswitch is located. A display portion of the display screen portrays images corresponding to screen positions that are associated with available input selections (commands or information). The display portion may also show a screen position being contacted, as a visual feedback to the user that an entry has been made.
As personal data devices may be quite small and compact, it follows that the screens are also small. Accordingly, each of the microswitches on the screen is quite small and they may be crowded quite closely together. Successfully entering a command is dependent upon having a suitable utensil for contacting the screen in a limited area in a manner that will operate a selected microswitch, but will not operate other, adjacent microswitches inadvertently. Typically, the personal data device is provided with an elongated stylus that is held in the user's hand and that may be placed in contact with the screen at a selected position to operate a microswitch to carry out a particular command or to enter data.
The conventional styli that are provide with personal data devices suffer from the problem of being easily lost. Although it is common for a personal data device to have a receptacle therein for storing its stylus, many users do not consistently replace the stylus in its storage receptacle when the device is not in use. The stylus is often perceived as a mere piece of plastic, and thus, is not carefully handled.
However, despite being inexpensive, the stylus is essential to the operation of the personal data device, so when the stylus is lost, a substitute must be found promptly. Waiting for the personal data device manufacturer to ship a new stylus is a substantial inconvenience. Besides, paying shipping charges for an inexpensive stylus is not economically efficient.
But there is no other suitable choice. Because the stylus is approximately the size and shape of a writing instrument, one may be tempted to replace a missing stylus with a writing instrument. This is not suitable because the working point of a writing instrument will damage the display screen of the device. Furthermore, the cap and butt end of the writing instrument are not precisely shaped so as to be effective as a stylus substitute. Since those portions of the writing instrument are not precisely shaped so as to activate only one microswitch at a time, they serve mainly to frustrate the user rather than provide for reliable input to the personal data device.
Another problem in the prior art is the inconvenience of switching back and forth between a writing instrument for working with paper-based media and a stylus for working with electronic media (i.e., a personal data device). The advent of personal data devices has the unfortunate side-effect of doubling the number of input tools that need to be kept track of: a pen and a stylus. Although hybrid devices for use with both types of media have been proposed, these proposals are all unsatisfactory because they do not solve the problem of how to retro-fit old writing instruments to be dual purpose.
Design Pat. No. Des. 390,872 shows an ornamental design for a combined computer input pen and writing instrument. It is a special purpose writing instrument that is formed with a writing tip fixed at one end and a computer input tip fixed at the opposite end.
Design Pat. Nos. Des. 355,440 and Des. 364,892 each show an ornamental design for a pen. In each case, the closed end of the cap has a rounded end that does not appear to be sufficiently pointy for effective use as a stylus for actuating microswitches of a touch screen.
Design Pat. No. Des. 402,690 shows an ornamental design for a stylus tip pen. It is a special purpose writing instrument that is formed with a computer input tip fixed at one end thereof, and having a retractable writing tip disposed at that same end. The pen has no cap.
Utility U.S. Pat. No. 4,778,302 shows a combination writing instrument and handcuff locking and unlocking device. It is a special purpose writing instrument that is formed with two retractable tips, which are alternately extendable from the same end of the writing instrument. One retractable tip is a writing element and the other retractable tip is a handcuff-locking element. It appears that the handcuff-locking element is not sufficiently pointy to be used as a stylus for a personal data device. The writing instrument has no cap.
Thus, what is needed is a convenient substitute for the stylus of a personal data device. What is also needed is a convenient way to modify conventional writing instruments to form a hybrid instrument that can be used as a stylus for a personal data device and as a writing instrument.